IL-2 is a soluble protein which has been found to influence cell-mediated immune responses in mammals; and in the past, has been produced by stimulating mouse, rat or human lymphocytes with a T cell mitogen. The immune responses which have been attributed to IL-2, include: (i) enhancement of thymocyte mitogenesis; (ii) production of alloantigen-directed cytotoxic T lymphocytes in spleen cell thymocyte and athymic nude mouse spleen cell cultures; (iii) promotion of long term in vitro proliferation of antigen specific helper or killer T cell lines; and (iv) promotion of anti-erythrocyte (red blood cell) plaque forming cell responses in nude mouse spleen cell cultures stimulated with sheep red blood cells.
From its ability to influence T cell dependent immune responses in vitro, it is thought that IL-2 plays a significant role in cell mediated immunity in vivo. The study of the in vivo capabilities of IL-2 has been hindered by the lack of reagents which are capable of detecting the presence of IL-2 serologically, as opposed to having to monitor its biological effect. Moreover, further examination not only of the molecular properties of this immunoregulatory molecule, but also of the biochemical comparisons between IL-2 and other lymphokine activities would benefit from the development of antibodies which react with IL-2. Accordingly, a principal object of the present invention is to develop a process for preparing an antibody which inhibits IL-2 activity which may be used to detect serologically its presence.